Ball Spin Parameter

Place any feature wishes for TrajectoWare Drive 2.0 here.

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yaretiree
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Ball Spin Parameter

Post by yaretiree » Sun Jun 10, 2007 7:31 pm

DaveT,
Great looking effort on initial quick scan!!!

I realize the difficulties in providing for different ball characteristics or even specific ball types (e.g., ProV1x). However, it may be useful to simply have a "Spin Rate Adjustment" Golf Ball Parameter.

This would be a +/- percentage adjustment to the baseline spin rate currently used.

I don't know enough about golf ball aerodynamics to know if this would do the trick. Perhaps a "Lift Adjustment" is also needed?

I was thinking that a user of the system might know the spin rate for their swing and particular ball and would be able to tweak things until they got the same results in TrajectoWare. Then they would be able to do more realistic trajectory comparisons.

At the very least they could see the impact of spin variations on their trajectories. [Ignore this reason, I see that this is easily accomplished already]

(I don't know if spin rate varies much by swing/ball speed, but it might be possible to have known simple adjustment factors for various types of balls. For example, someone reports in the Forum that for a ProV1 increase the spin rate by 5%).
/Ed

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Re: Ball Spin Parameter

Post by dtutelman » Mon Jun 11, 2007 11:30 pm

yaretiree wrote:DaveT,
I realize the difficulties in providing for different ball characteristics or even specific ball types (e.g., ProV1x). However, it may be useful to simply have a "Spin Rate Adjustment" Golf Ball Parameter.
Hi, Ed!
Glad to hear you like it.

Ball characteristics are on our wish list, but are below things like bounce/roll, and increasing the range of spin we can handle. Actually, I suspect that the research to deal properly with spin may throw more light on how to deal with ball differences as well.

Actually, I'm a little torn about the controls you suggest.
  • On the one hand, I'm reluctant to add it to the program if I can't relate it to reality in the manual (the help file). And right now I can't in any useful way.
  • On the other hand, I do use things like spin and drag controls as "what if" items in Max Dupilka's trajectory program. While I might not be able to relate it to anything practical, it gives me something to think about.
Cheers!
DaveT

yaretiree
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Post by yaretiree » Tue Jun 12, 2007 1:47 am

DaveT,
Is there a generic description of the baseline ball? Is it like a 2-piece distance ball or a 3-piece "tour" ball? This would provide some help in interpreting the results.

Also, if the type of baseline ball were known, then it makes some sense to be able to specify a percentage change (spin, lift, drag, ?) for the type of ball you normally play.

I realize that this would be a guessing game at first, but it would give you a straight forward way to change the characteristics once more ball information was known.

Question: Does it even make any sense to worry about the ball when determining the proper driver? Put another way could you come up with a "perfect" driver, based upon the trajectory results, and then the characteristics of the golfer's ball invalidate your choice?

If the golfer's real ball characteristics don't make a difference in determining the proper driver, then give ball characteristics a low priority. If the real ball characteristics can make a difference in the selection of the proper driver, then they should be given a higher priority. (At least that is what makes sense to me).
/Ed

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Post by dtutelman » Tue Jun 12, 2007 7:23 pm

yaretiree wrote:DaveT,
Is there a generic description of the baseline ball? Is it like a 2-piece distance ball or a 3-piece "tour" ball?
We got the algorithm from Adams. If I read between the lines of his presentation to the ASME, I'd have to guess it's a Titleist Pro-V1x. But I can't be sure.
Question: Does it even make any sense to worry about the ball when determining the proper driver? Put another way could you come up with a "perfect" driver, based upon the trajectory results, and then the characteristics of the golfer's ball invalidate your choice?
Good thinking, Ed.

I tried the following, using Max Dupilka's trajectory program which allows playing with these parameters. I optimized loft with a "nominal" ball. Then I increased the spin coefficient by 15%. (That's quite a bit.) The optimum loft was 1* lower than before. Not the same, but the difference is really small. Then I restored the spin coefficient and increased the lift coefficient by 15%. This time I got a LARGE increase in carry distance -- but the loft for optimum carry was still only 1* less than for the nominal ball.

My conclusion: the ball can make a significant difference in the carry, but only small differences in the parameters of the driver that produces maximum carry. And that was your point. I know you were hoping it would produce no difference at all; that was not the case.

Thanks,
DaveT

RickinMA
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Post by RickinMA » Mon Jan 07, 2008 11:24 pm

Having played around with the software for a few minutes, it looks great, so I wanted to thank you.

I too was curious about the spin properties of the ball. I can appreciate the comments above, but can't help but think a player should first pick a ball based on the shortgame/scoring, then fit the driver to achieve the desired launch.

I think Tom Wishon's book talked about selecting the lowest loft that maximizes (or close to maximizes) carry, in an attempt to reduce angle of decent and pick up some yards with roll. I would think the balls inherent spin characteristics will impact the angle of decent, but could be mistaken.

I suppose the same type of differences could arise if fitting a player with range balls or a low-spin distance ball. If that player takes your recommendations, then goes out and tees up a high-spin ball, I would think some "ballooning" could happen out on the course and they may not be as satisfied with the fitting as they otherwise could have been.

Thanks

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Post by dtutelman » Fri Jan 11, 2008 4:08 am

RickinMA wrote:I too was curious about the spin properties of the ball. I can appreciate the comments above, but...

I think Tom Wishon's book talked about selecting the lowest loft that maximizes (or close to maximizes) carry, in an attempt to reduce angle of decent and pick up some yards with roll. I would think the balls inherent spin characteristics will impact the angle of decent, but could be mistaken.

I suppose the same type of differences could arise if fitting a player with range balls or a low-spin distance ball. If that player takes your recommendations, then goes out and tees up a high-spin ball, I would think some "ballooning" could happen out on the course and they may not be as satisfied with the fitting as they otherwise could have been.
I think that's what I did in the exercise I described above. It turned out there was a difference in the loft for optimum carry, but it was a very small difference for large differences in balls.

If you are determined to follow that line of questioning, send me private email and I can send you a copy of Max's program. Then you will try to find cases for which the optimum loft has large changes.

It would not be that hard to include a lift coefficient and a spin coefficient in the next version of TrajectoWare Drive. The big problem -- and the reasons we might choose not to include this feature -- is that it is much harder to relate those coefficients to actual models of balls, or even to a realistic range for commercial golf balls.

Cheers!
DaveT

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